Castle Danger is a 2-player, turn-based, full-information, strategy game. It is played on a rectangular board, divided into squares -- 9 columns by 7 rows. The middle column on the board is an impassible river, leaving each player with a 4x7 section of the board on which to control their pieces. Six (6) different types of pieces are used in the game: a single King per player (must be protected), Wizards (gives the player more moves to use each turn), Builders (add/remove Walls from the board), Cannons (shoot cannonballs at opponent's pieces), Walls (intercept cannonballs -- used to give protection to other pieces), and Fire (placed on the board wherever a cannonball lands). If a player's "portal" square (the middle square in their outside column) is open at the start of the turn, the player can add a new piece on that square. The first player to hit their opponent's King with a cannonball is the winner. The game was first published as a 2-player computer game, which can be played against an opponent over the Internet. Now there is also a tabletop version of the game available, which includes rules for a hidden-information variant.